This invention relates to the manufacture of turbine elements such as airfoils like blades and vanes. More particularly the invention relates to the manufacture of turbine elements via integration of multiple components.
A variety of manufacturing techniques are used to make metallic components of gas turbine engines such as blades and vanes. One family of techniques involves investment casting. However, some component materials are not readily susceptible to investment casting. With such materials, machining from ingots or other stock is required. Direct machining imposes severe constraints on the flexibility to machine internal features. Accordingly, it is known to machine components in pieces and then integrate the pieces via diffusion bonding. Examples of diffusion bonding in turbine blade formation (e.g., using Ti-6Al-4V) are found in U.S. Pat. Nos. 5,063,662 and 5,711,068. The '662 patent discloses a detailed process for forming a twisted hollow blade having internal structure. The process involves the diffusion bonding of two blade halves followed by additional deformation and machining. The '068 patent discloses a specific situation in which the two blade halves are cut from a single piece and are diffusion bonded with uncut surfaces facing each other. Nevertheless, there remains room for improvement in the art.